Taxpayer registration and identification is critical for the effective operation of a tax system. This chapter comments on some of the significant characteristics of these processes.
Tax Administration 2025
Comparative Information on OECD and other Advanced and Emerging Economies
Abstract
A comprehensive system of taxpayer registration and identification is at the foundation of an effective tax system. It is the basis for supporting a wide range of core tax administration work such as self-assessment, value-added tax and withholding tax regimes, as well as third party reporting and data matching. This chapter picks out several issues of significance in taxpayer registration and identification, including levels of registration, registration channels and identity management, and how digital transformation affects these services.
The fundamental importance of an effective tax registration system cannot be overstated. These processes need to both manage those taxpayers that are “part of the system” and to help identify those yet to register. Furthermore, they need to be able to monitor and determine actions and interventions to establish any liability to tax for both individuals and corporate bodies, even in systems where filing is not mandatory.
Figure 3.1. provides information on the rate of registered personal taxpayers as a percentage of the total population. This shows a wide range of registration rates, often reflecting the level of integration the tax administration has with other parts of government, as well as income thresholds for tax purposes.
Source: ADB, CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Table D.19 Registration of personal income taxpayers, http://isoradata.org (accessed on 1 October 2025).
While the majority of administrations are solely responsible for the system of registration for tax purposes within their jurisdictions, previous editions of this series have shown that in many jurisdictions the registration processes can also be initiated outside of the tax administration through other government agencies (OECD, 2019[1]).
In looking at how taxpayers can register, all administrations reported they provide more than one channel for taxpayers to use and 98% report that it is possible to register online (see Table 3.1.). Compared to the 2014 data included in the 2017 edition of this series (OECD, 2017[2]), this is a 35-percentage point increase, and it illustrates the advances in digitalisation over the 10-year period between 2014 and 2023.
Although in-person registration continues to be an important channel or element of the registration process (often due to the need to provide physical evidence of identity), it is expected that as digital identity systems become more sophisticated and embedded within government systems, the range of digital channels will grow.
Percentage of administrations that provide the respective registration channel
Note: The registration channels may not always be available for all tax types or taxpayer segments.
Source: ADB, CIAT, IOTA, IMF, OECD, International Survey on Revenue Administration, Tables A.94 Registration channels: Online, Telephone, Email, and A.95 Registration channels: Mail / post, In-person, other, http://isoradata.org (accessed on 1 October 2025).
While the underlying survey does not allow identification of whether the online registration channel is available for all tax types or taxpayer segments, jurisdictions report that it is being integrated in their ongoing digital transformation process. This shift to digital channels may also help drive further efficiencies, though as the shift to digital gathers pace further attention is being paid to those who may not have access to digital services.
Given the pivotal role that registration and taxpayer identification play in underpinning the tax system, having up-to-date tax registers remains a high priority for most tax administrations. As past editions have shown, the large majority of administrations have formal programmes in place to improve the quality of the tax register (OECD, 2019[1]).
Therefore, it is unsurprising that other government bodies may wish to use the tax administration register for their own purposes to provide services or ensure compliance with laws and regulations. This is leading to the creation of cross government databases. As data from the 2025 OECD report Tax Administration Digitalisation and Digital Transformation Initiatives (OECD, 2025[3]) illustrates, 76% of administrations report the existence of a range of such databases, for example, population or business registers (see Table 3.2.).1
Percentage of jurisdictions
Source: OECD (2025), Tax Administration Digitalisation and Digital Transformation Initiatives, Table 4.7., https://doi.org/10.1787/c076d776-en.
Data integration across government is further increasing as governments see the potential in using information maintained by tax administrations, such as taxpayer address and bank information, to contact citizens and businesses or to make direct benefit or support payments (OECD, 2020[4]). As a result of this closer collaboration between government agencies, many of them are integrating (parts of) their IT systems to make tax registration part of other actions taxpayers undertake. For example, registering for tax at the same time as registering a company or registering the birth of a child. Further, there is a growing trend that the digital identities that taxpayers create as part of the registration process provides access to services from other parts of government or third parties (see Table 3.3.).
Percentage of administrations that have the respective process in place
Source: OECD (2025), Tax Administration Digitalisation and Digital Transformation Initiatives, Table 2.1., https://doi.org/10.1787/c076d776-en.
All tax administrations, whether required to by law or as a matter of sound business practice, put considerable effort into ensuring the security of taxpayer information. In addition to internal processes to prevent unlawful attempts to obtain information and to ensure taxpayers’ rights are protected, all administrations have processes to ensure the person they are dealing with is in fact the taxpayer or their authorised representative. Increasingly these approaches, which in many instances have now been extended to multi-factor authentication, are making use of biometric information, unique to the taxpayer.
For example, in relation to online services, Table 3.4. shows that administrations use some type of authentication method to verify the digital identity. The type of verification method varies. As can be seen in Table 3.4., password-based authentication is used by 77% of administrations, followed by multi-factor authentication, mobile app and ID card. A few administrations also reported using facial recognition or fingerprint recognition to authenticate the digital identity of a taxpayer. Two-thirds of the administrations reported that their use of different authentication methods is based on the level of security required for certain types of interactions.
Percentage of administrations that have the respective process in place
Source: OECD (2025), Tax Administration Digitalisation and Digital Transformation Initiatives, Table 2.4., https://doi.org/10.1787/c076d776-en.
Tax administrations face similar challenges to other organisations in dealing with individuals or organisations that may misuse personal information to impersonate taxpayers in order to commit fraud. The rise of AI enabled image and audio generators will complicate this even further. The on-going and, in many cases, organised nature of this activity is requiring administrations to devote considerable effort to the prevention of identity theft.
Austria - Digital identity verification and secure customer communication in the financial sector
The Austrian Ministry of Finance has increasingly utilised digital solutions to make access to its online portal (FinanzOnline) more secure and efficient. A key milestone was the introduction of regular video appointments, providing an alternative to in-person visits. Customers and employees can attend these meetings from any location, with identification carried out via ID Austria. The technical implementation builds on established video conferencing solutions and integrates seamlessly with existing appointment scheduling systems.
Building on these experiences, the Video-Ident procedure was developed to serve taxpayers who cannot use ID Austria or other European Union compliant identification methods. Identity verification is conducted via video and is supported by an external database for verifying international identity documents. Trained staff carry out the standardised process, with appointments available in both German and English. A dedicated regulation provides the legal framework for this service, making it a secure alternative to in-person visits at tax offices, particularly benefiting users abroad who need access to FinanzOnline.
Simultaneously, customers can now securely retrieve personalised information and update their personal data via phone or chat. The secure authentication ensures that sensitive inquiries are processed efficiently while maintaining a focus on data protection and user-friendliness. In the field of telephone authentication in particular, this enables the secure and seamless handling of confidential information for the first time.
Canada – Digital identity validation
The Canada Revenue Agency’s (CRA) Digital Identity Validation (DIV) service leverages AI to validate user identities online, providing a seamless method for gaining instant full access to the CRA’s online services. It eliminates the need for a user to wait for a physical code to be sent by mail, which typically takes up to 10 business days to arrive, and allows users to self-serve and gain immediate access to online services, enhancing convenience and efficiency.
Since its launch, 60% of users have opted to use DIV over the traditional mail option. This shift has reduced the workload on call centres, decreased paper mail which can be costly, and reduced processing times, allowing staff to focus on other more complex tasks.
In the future, the focus will be on expanding use cases and enhancing the DIV solution to support additional parts of CRA services such as streamlining account recovery processes.
Japan – Digital certificates for smartphones
To make it easier for taxpayers to verify their identity online, Japan has introduced digital certificates for smartphones. This removes the need to use a physical card when filing individual income tax returns online. Online tax-return filing using the physical card in Japan comprised around 70% of all online tax returns filed at home in 2023.
“Digital certificates for smartphones” is a service that allows taxpayers to certify their identity using their smartphones, by installing digital certificates with an equivalent personal identification function on smartphones (only available on smartphones with certain operating systems as of February 2025). This simplifies the verification process and increases convenience for taxpayers, reducing the burden when it comes to filing tax returns.
Netherlands - Using digital identification and wallets: electronic invoicing
The Netherlands Tax Administration (NTA) is exploring the use of digital identity and wallets, in alignment with the Tax Administration 3.0 vision. The aim is to collaborate with stakeholders to improve seamless and trustworthy business transactions. One example of where this can be effective is in electronic invoicing (e-invoicing), which faces challenges such as diverse protocols and varying identifiers and reliance on intermediaries.
Initial experiments utilised the European Blockchain Services Infrastructure Trust Registry for issuing verifiable credentials and demonstrating interoperability among organisational wallets. Additionally, a pilot project showcased the interaction between personal and organisational wallets, and the use of the VAT identification number to verify the existence of online shops. Currently, the NTA is developing a decentralised address book for verified metadata and selective disclosure mechanisms for e-invoices. Future developments include integrating organisational wallets with bookkeeping software and enterprise resource planning systems for automated invoice verification.
For further information, please see the following links: https://companypassport.com/ and https://fides.community/ (accessed on 1 October 2025).
United Kingdom – Repayment agent registration
To improve His Majesty’s Revenue and Customs’ (HMRC) performance and overall customer experience, a commitment was made by United Kingdom (UK) ministers to introduce a new requirement for paid income tax repayment agents to register with HMRC. This was part of wider work to explore options to enhance the regulatory framework for tax advice and tax services.
Previously, paid tax agents who specialised in submitting income tax repayment claims on behalf of their customers used paper forms and did not need to register with HMRC. This was in contrast with other agents who use HMRC digital services. This limited HMRC’s ability to proactively check if the agent was registered for anti-money laundering supervision and whether they met the HMRC standard for agents before processing their claims.
Introduced in February 2024, HMRC now has the capability to link paper tax relief claim forms to digital registration processes, strengthening HMRCs commitment to ensuring no unregistered repayment agents are actively submitting claims without the consent of the taxpayer. These changes aim to reduce associated customer complaints annually (2024-2025) by 40%, with a target of issuing repayments to the correct person running at 99.98% by September 2024. The progress resulted in HMRC mandating agents to use its Agent Services Account registration process for all work relating to income tax, to ensure they can track who is an agent and that they meet the right standards.
Sources: Austria (2025), Canada (2025), Japan (2025), the Netherlands (2025) and the United Kingdom (2025).
References
[3] OECD (2025), Tax Administration Digitalisation and Digital Transformation Initiatives, OECD Publishing, Paris, https://doi.org/10.1787/c076d776-en.
[4] OECD (2020), “Tax administration responses to COVID-19: Assisting wider government”, OECD Policy Responses to Coronavirus (COVID-19), OECD Publishing, Paris, https://doi.org/10.1787/0dc51664-en.
[1] OECD (2019), Tax Administration 2019: Comparative Information on OECD and other Advanced and Emerging Economies, OECD Publishing, Paris, https://doi.org/10.1787/74d162b6-en.
[2] OECD (2017), Tax Administration 2017: Comparative Information on OECD and Other Advanced and Emerging Economies, OECD Publishing, Paris, https://doi.org/10.1787/tax_admin-2017-en.
[5] OECD et al. (2025), Inventory of Tax Technology Initiatives, https://www.oecd.org/content/oecd/en/data/datasets/inventory-of-tax-technology-initiatives.html (accessed on 1 October 2025).
← 1. The 2025 OECD publication Tax Administration Digitalisation and Digital Transformation Initiatives (OECD, 2025[3]) summarises the data from the Inventory of Tax Technology Initiatives (OECD et al., 2025[5]) for the 54 members of the OECD Forum on Tax Administration.